WORKING:
Send a message to userA@B-domain (gets to userA@B-domain)
Send a message to userA@A-domain (gets to userA@B-domain)
Send a message to userB@B-domain (gets rejected)

NOT WORKING:
Send a message to userB@A-domain (creates userB in the B-domain folder, but should be rejected because userB doesn't exist @B-domain. Over time I have tons of Maildir folders with mistyped users@alias-domains that have to be cleaned up..

Will continue to find possible mail drop issues that might be breaking in the mail user verify through alias domains..